HMX FJ400 Linear Switches

The HMX FJ400 is a linear mechanical switch suited for users seeking a moderate typing force with a balanced sound profile. It fits well for typists and enthusiasts who want a noticeable but not overwhelming clack sound, making it adaptable to various environments. Its medium actuation force supports longer typing sessions without causing fatigue.

Feel and Sound

• The switch offers a smooth, linear keystroke without tactile bumps or clicks.
• It produces a medium clack sound that is audible yet not overpowering, suitable for shared spaces.
• The combination of polycarbonate top and nylon bottom housings contributes to a deep, full bottom-out sound.

Actuation Characteristics

• Requires moderate force to actuate, balancing responsiveness and comfort.
• Pre-travel of 2.0mm and total travel near 3.8mm provide a standard keypress distance.
• Bottom-out force is slightly higher than actuation force, offering a consistent feel when fully pressed.

Build Quality

• Uses a T2 stem known for durability and smoothness.
• Polycarbonate top housing and nylon bottom housing improve sound and longevity.
• Includes a 22mm single-stage spring for consistent keystrokes.
• Factory-lubed with GPL105 and GPL205, reducing initial scratchiness and improving smoothness.

Compatibility and Use Cases

• Features a 5-pin PCB mount, ensuring stable installation in custom builds.
• Good choice for typists and users who want a balanced sound without excessive noise.
• Less ideal if a silent or tactile switch is preferred, or if very light actuation is needed.